Supplemental wages refer to compensation paid to employees in addition to their regular wages or salary. These payments are typically irregular or non-recurring and can include bonuses, commissions, overtime pay, severance pay, and fringe benefits. In the field of human resources, understanding how to calculate, report, and withhold taxes on supplemental wages is essential for compliance with tax regulations.

Example
Imagine an employee named John receives a year-end bonus of $5,000 on top of his regular monthly salary of $4,000. In this case, the $5,000 bonus is considered supplemental wages. To ensure proper tax withholding, the employer may use different tax withholding methods, such as the flat rate method or the aggregate method, depending on the amount of the supplemental wages and the employee's total annual income. Understanding and correctly handling supplemental wages is crucial for both employers and employees to comply with tax laws.